Born in Dublin, the second son of James Willey and Emily Maud Bannister, he joined the Rifle Brigade soon after the outbreak of war.

The 14th and 3rd Divisions were ordered to attack the strong German positions at Bellewaarde Farm, near Hooge, that overlooked the British line.

The battalion was then in a highly exposed and unsupported position, taking very heavy casualties, eventually losing all but four officers and one hundred and forty men.

Col Villiers-Stuart's diary relates: A very young sergeant of D Coy, Will[e]y by name, had done specially well in the disastrous fight and was the first of the New Army to be made a CSM.

B/2391 Serjeant H.J.Willey, 9th Battalion, Rifle Brigade.For conspicuous gallantry and ability on the 25th September, 1915, on Bellewaarde Ridge.

During the action Serjeant Willey passed continually backwards and forwards trying to establish communication with the Battalion on his right, and later, when all his Officers had been killed, he rallied and organised the men of his own and other Companies, and captured a position in the German second line trenches, which he held against all counter attacks.

[d]Such actions, including Willey's, were widely reported in the British press at the time as examples of how men in junior ranks had exercised initiative and leadership after their units had suffered high casualties amongst their officers - for example an article entitled Gallant Deeds Rewarded - Leaders in the Ranks published by The Buckingham Advertiser and North Bucks Free Press in November 1915.

This serjeant, Willey by name, collected a few stragglers of other battalions and held a post at the north end of the copse, but south of the Menin Road, until relieved.

During much of the 1920s and '30s, Willey served as a detective in Special Branch,[17] earning several commendations for arrests in firearms and other cases.

In 1921 Willey was serving in the short-lived Home Office Directorate of Intelligence under Sir Basil Thomson.

[18]: Chp 13  During the Second World War Willey was awarded the King's Commendation for Brave Conduct for his actions during the London Blitz.